/*
 * Copyright 2006-2011 the original author or authors.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 */
package org.springframework.security.oauth2.common.exceptions;

import java.io.IOException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.codehaus.jackson.JsonParser;
import org.codehaus.jackson.JsonProcessingException;
import org.codehaus.jackson.JsonToken;
import org.codehaus.jackson.map.DeserializationContext;
import org.codehaus.jackson.map.JsonDeserializer;
import org.springframework.security.oauth2.common.util.OAuth2Utils;

/**
 * @author Dave Syer
 * 
 */
public class OAuth2ExceptionJackson1Deserializer extends JsonDeserializer<OAuth2Exception> {

	@Override
	public OAuth2Exception deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException,
			JsonProcessingException {

		JsonToken t = jp.getCurrentToken();
		if (t == JsonToken.START_OBJECT) {
			t = jp.nextToken();
		}
		Map<String, Object> errorParams = new HashMap<String, Object>();
		for (; t == JsonToken.FIELD_NAME; t = jp.nextToken()) {
			// Must point to field name
			String fieldName = jp.getCurrentName();
			// And then the value...
			t = jp.nextToken();
			// Note: must handle null explicitly here; value deserializers won't
			Object value;
			if (t == JsonToken.VALUE_NULL) {
				value = null;
			}
			// Some servers might send back complex content
			else if (t == JsonToken.START_ARRAY) {
				value = jp.readValueAs(List.class);
			}
			else if (t == JsonToken.START_OBJECT) {
				value = jp.readValueAs(Map.class);
			}
			else {
				value = jp.getText();
			}
			errorParams.put(fieldName, value);
		}

		Object errorCode = errorParams.get("error");
		String errorMessage = errorParams.containsKey("error_description") ? errorParams.get("error_description")
				.toString() : null;
		if (errorMessage == null) {
			errorMessage = errorCode == null ? "OAuth Error" : errorCode.toString();
		}

		OAuth2Exception ex;
		if ("invalid_client".equals(errorCode)) {
			ex = new InvalidClientException(errorMessage);
		}
		else if ("unauthorized_client".equals(errorCode)) {
			ex = new UnauthorizedClientException(errorMessage);
		}
		else if ("invalid_grant".equals(errorCode)) {
			if (errorMessage.toLowerCase().contains("redirect") && errorMessage.toLowerCase().contains("match")) {
				ex = new RedirectMismatchException(errorMessage);
			}
			else {
				ex = new InvalidGrantException(errorMessage);
			}
		}
		else if ("invalid_scope".equals(errorCode)) {
			ex = new InvalidScopeException(errorMessage);
		}
		else if ("invalid_token".equals(errorCode)) {
			ex = new InvalidTokenException(errorMessage);
		}
		else if ("invalid_request".equals(errorCode)) {
			ex = new InvalidRequestException(errorMessage);
		}
		else if ("redirect_uri_mismatch".equals(errorCode)) {
			ex = new RedirectMismatchException(errorMessage);
		}
		else if ("unsupported_grant_type".equals(errorCode)) {
			ex = new UnsupportedGrantTypeException(errorMessage);
		}
		else if ("unsupported_response_type".equals(errorCode)) {
			ex = new UnsupportedResponseTypeException(errorMessage);
		}
		else if ("access_denied".equals(errorCode)) {
			ex = new UserDeniedAuthorizationException(errorMessage);
		}
		else if ("insufficient_scope".equals(errorCode)) {
			ex = new InsufficientScopeException(errorMessage, OAuth2Utils.parseParameterList((String) errorParams
					.get("scope")));
		}
		else {
			ex = new OAuth2Exception(errorMessage);
		}

		Set<Map.Entry<String, Object>> entries = errorParams.entrySet();
		for (Map.Entry<String, Object> entry : entries) {
			String key = entry.getKey();
			if (!"error".equals(key) && !"error_description".equals(key)) {
				Object value = entry.getValue();
				ex.addAdditionalInformation(key, value == null ? null : value.toString());
			}
		}

		return ex;

	}

}